Commit | Line | Data |
---|---|---|
3b600ead TL |
1 | #include <stdio.h> |
2 | ||
3 | #define NL '\n' | |
4 | #define CLEAR 014 | |
5 | #define HOME 031 | |
6 | #define BACK 037 | |
7 | #define BUFMAX 16384 | |
8 | #define PAGMAX 64 | |
9 | ||
10 | int file; | |
11 | int cp, hp; | |
12 | int page[PAGMAX]; | |
13 | int eof; | |
14 | ||
15 | char buf[BUFMAX]; | |
16 | int bptr, bnxt, bend; | |
17 | ||
18 | ||
19 | #define incr(a,b) (a++, a&=b-1) | |
20 | #define decr(a,b) (a--, a&=b-1) | |
21 | ||
22 | ||
23 | main(argc,argv) | |
24 | char *argv[]; | |
25 | { | |
26 | int n=1; | |
27 | if(argc<2) | |
28 | print(); | |
29 | else { | |
30 | while(argv[n]!=-1) { | |
31 | if((file=open(argv[n],0))>=0) { | |
32 | print(); | |
33 | close(file); | |
34 | } else printf("dk: `%s' cannot open\n",argv[n]); | |
35 | n++; | |
36 | } | |
37 | } | |
38 | } | |
39 | ||
40 | print() | |
41 | { | |
42 | register int nlc; | |
43 | char buf[2]; | |
44 | ||
45 | hp=0; cp=0; | |
46 | bptr=bnxt=bend=0; | |
47 | putchar(CLEAR); | |
48 | for(;;) { | |
49 | setpage(); | |
50 | nlc=0; | |
51 | putchar(BACK); | |
52 | while(nlc<20) { | |
53 | char c; | |
54 | c = readchar(); | |
55 | if(eof) | |
56 | return; | |
57 | if(c==NL) nlc++; | |
58 | putchar(c); | |
59 | } | |
60 | while(read(2,buf,1)==1 && buf[0]!=NL) { | |
61 | switch(buf[0]) { | |
62 | case '/': | |
63 | case HOME: | |
64 | putchar(CLEAR); | |
65 | getpage(0); | |
66 | break; | |
67 | case '-': | |
68 | case BACK: | |
69 | getpage(-1); | |
70 | putchar(CLEAR); | |
71 | break; | |
72 | case '!': | |
73 | shell(); buf[0]=NL; break; | |
74 | } | |
75 | } | |
76 | } | |
77 | } | |
78 | ||
79 | ||
80 | #include <signal.h> | |
81 | #define EOR '\n' | |
82 | shell() | |
83 | { | |
84 | int rc, status, unixpid; | |
85 | if( (unixpid=fork())==0 ) { | |
86 | close(0); dup(2); | |
87 | execl("/bin/sh", "sh", "-t", 0); | |
88 | exit(255); | |
89 | } | |
90 | else if(unixpid == -1) | |
91 | return(0); | |
92 | else{ signal(SIGINT,SIG_IGN); signal(SIGQUIT,SIG_IGN); | |
93 | while( (rc = wait(&status)) != unixpid && rc != -1 ) ; | |
94 | signal(SIGINT,SIG_DFL); signal(SIGQUIT,SIG_DFL); | |
95 | return(1); | |
96 | } | |
97 | } | |
98 | ||
99 | readchar() | |
100 | { | |
101 | register char c; | |
102 | if(bnxt==bend) | |
103 | fillbuf(); | |
104 | if(eof) | |
105 | return(-1); | |
106 | c=buf[bnxt]; | |
107 | incr(bnxt,BUFMAX); | |
108 | return(c); | |
109 | } | |
110 | ||
111 | fillbuf() | |
112 | { | |
113 | register int r; | |
114 | register int len; | |
115 | ensure(); | |
116 | if(eof) | |
117 | return; | |
118 | r=read(file,&buf[bend],512); | |
119 | if(r==-1) | |
120 | return; | |
121 | bend += r; bend &= BUFMAX-1; | |
122 | if(r==0) | |
123 | eof++; | |
124 | return; | |
125 | } | |
126 | ||
127 | ensure() | |
128 | { | |
129 | for(;;) { | |
130 | if(bptr<=bend) | |
131 | return(BUFMAX-bend-1); | |
132 | if(bptr-bend>=512) | |
133 | return(512); | |
134 | losepage(); | |
135 | } | |
136 | } | |
137 | ||
138 | losepage() | |
139 | { | |
140 | if(hp<cp) | |
141 | bptr=page[incr(hp,PAGMAX)]; | |
142 | } | |
143 | ||
144 | setpage() | |
145 | { | |
146 | incr(cp,PAGMAX); | |
147 | if(cp==hp) | |
148 | incr(hp,PAGMAX); | |
149 | page[cp]=bnxt; | |
150 | } | |
151 | ||
152 | getpage(i) | |
153 | { | |
154 | if(i==0) | |
155 | cp=hp; | |
156 | else if(cp!=hp) | |
157 | decr(cp,PAGMAX); | |
158 | bnxt=page[cp]; | |
159 | } |